please i need the answers in this week ,reply me.

[bayan1]

why we use mixer ,rf amp,if amp,in earth station receiver???
and what is the meaning of carrier freguecy??
also, please give me practical examples on digtal and analog signals ??(the difference between them??

 

[ferdinand_leo]

for you 1st line of questions...
visit: https://en.wikipedia.org/wiki/Frequency_mixer

carier frequency signal is usually the higher frequency signal compared to the modulating frequency. It is called carier because it caries the information signal.
for example, in FM radio: The carrier frequency would be around 88 to 108MHz,
while the modulating frequency is the information being transmitted which is audio.

digital signals are defined as discreet signals with defined levels. either 1 or 0...
analog signals are those signals continuous in nature, eg sinewave, which the amplitude varies with respect to time.